Telephone system



June 14, 1932 F. LUBBERGER ET AL 1,862,689

TELEPHONE SYSTEM Filed Aug. 5, 1931 JET Inuanlclr's FEE Lubberger' Ear-hard HEThE'Fl' coil.

Patented June 14, 1932 uurrrn sures PATEN DFFICE FRITZ LUBBERGEB AND GERHARD RO'IHERT, OF BERLIN, GERMANY, ASSIGNORS 'I'O MANY TELEPHONE SYSTEM Application filed August 3, 1931, Serial No. 554,701, and in Germany November 21, 1930.

T he-invention relates to a circuit arrangement for the transmission of signals over inductively connected junction lines in telephone systems. 7

The invention is based on the fact that, according to the direction of current generated in the primary winding of a repeating coil, an induced current in a certain direction is set up in the secondary winding of the The invention makes use of this fact in the case of an impulse series to solve in a simple manner the problem of producing various signals according to the type of impulses transmitted over inductively connected lines. This is achieved by means of switching devices arranged at the outgoing end of the junction line transmitting impulses of a certain direction over the line and the received impulses being converted into dilierent signals according to their direction by means of switching devices provided at the incoming end of said line.

An embodiment of the invention is shown in the drawing. This operates as follows:

lVhen contact 1i at the outgoing endoi the junction line VL is repeatedlyoperated, for example, by means of the dial, relay A is repeatedly energized, consequently operating contact 2a. A momentary flow of current in a certain direction is then set up in the primary winding of the repeating coil U61. This induces an impulse in the secondary winding of this repeating coil in known manner whlch might be caused to travel for example,

as follows: from the secondary winding, contacts 37b2, ethl, primary winding of the repeating coil U62, contact 5h1, and back to the secondary winding of the repeating coil U61. This regenerates a momentary current in the secondary winding of the repeating coil U62 which is transmitted by the junction line VL to the repeating coil U63, generating an impulse in a a certain direction in the secondary winding of the said repeating coil, which impulse reaches the impulse receiving relay E1 over the rectifier G1 and causes the said impulse receiving relay to be energized. Relay E1,

7 when energized, closes contact 661, which in turn causes relay S1 to be energized. This relay closes contact 781, which completes a circuit for the lamp L1, which is thus lighted every time contact 2a is closed. If relay A is repeatedly deenergized when contact 11' is actuated, a current is induced in the secondary winding of the repeating coil U61 every time contact 2a is opened. As these currents, however, flow in a direction opposite to the current generated at contact 2a, the direction of the impulses generated in repeating coils U62 and U63 will correspond. Therefore, relay IE1 at the incoming end of the junction line will no longer be influenced as the rectifier G1 blocks the energizing circuit of this relay for this current direction. The impulses from the rectifier G2, on the other hand, can pass freely and in consequence repeatedly energize relay E2. This relay closes contact 1062, thereby closing a circuit for relay S2 a corresponding number of times. Relay S2 is energized at each closing of contact 1062 and by closing contact 1152 causes the lamp L2 to light up. Being designed as a slow-acting relay, it remains energized during the impulse series and thus causes the lamp L2 to burn continuously.

It will thus be seen that a flickering light from the lamp L1 and a continuous light from lamp L2 is obtained at the incoming end of the junction line when contact 1i at the outgoing end of the junction line is actuated for the purpose of signalling.

If now the keys T1 and T2 also are permanently depressed while signals are transmitted by contact 12' being actuated, the following operations take place:

By the closing of the circuit for relay H1 by means of the key T1 the contacts 1h1 and 5h1 are thrown over into positions 8h1 and 9h1. By the closing of the circuit for relay H2 this relay is energized which results in contact 3h2 being thrown over into position 12h2. When contact 2a is repeatedly closed, the impulse induced in the secondary winding of the repeating coil U61 travels over contact 12b2, rectifier G3, contact 87b1, primary winding of the repeating coil U62. contact 97b1, and back to the secondary winding of the repeating coil U61. An impulse the closing of r will therefore pass through the primary Winding of the repeating coil U62 in another direction than explained in the above as being generated at the closing of contact 2a. At the incoming end of the junction line relay E2, and not relay E1, is energized by the impulses generated by the closing of contact 2a. Relay E2 rec-loses contact 1062 which in turn causes relay S2 to be energized, the said relay S2 remaining energized during the impulse series, thus causing the lamp L2 to burn continuously. The impulses induced in the secondary winding of the repeating coil Uel at the release of relay A, however, are blocked by the rectifier G3 as this only passes impulses travelling in the other direction.

11 this manner, when signalling by the repeated actuating of contact 12' with the keys T1 and T2 closed, the lamp L2 will burn continuously.

If the key T2 only is permanently depressed while contact 12' is actuated, the following operations take place:

y the energization of relay H2, contact 3&2 is again thrown over into position 12h2. Contacts l/Ll and 5711, however, remain closed. At each energization of relay A an impulse is induced in the secondary winding of the repeating coil U61 due to the generated impulse in the primary winding of this coil, the said induced impulse travelling over contact 12b2, rectifier G3, contact 4711, primary winding of the repeating coil U62, contact 45b1, and back to the repeating coil Ucl. Thereby an impulse is induced in the secondary winding of the repeating coil U62 and transmitted to the repeating coil U63 over the junction line. The impulses induced in this manner in the secondary circuit of this repeating coil influence. relay E1, whereupon relay S1 is repeatedly energized, causing the lamp L1 to flicker. The impulses induced in the secondary winding of the re peat-ing coil Uel upon the deenergizations of relay A will have no etlect as they are blocked by the rectifier G3.

Thus, when signalling by repeated actuation of contact 12' with key T2 closed, the lamp L1 will be caused to flicker.

\Vhat is claimed is:

1.- In a signal transmission system, a trunk line, switching devices inductively connected to one end of the trunk line for transmitting current impulses of different polarity over the trunk line, signals at the other end of the trunk line,-and discriminating means at said other end of the trunk line responding to the current impulses in accordance with their polarity to operate one of the signals corresponding with the polarity of the received impulses.

2. In a signalling system, a trunk line, means inductively connected to one end of the trunk line for transmitting impulses thereover, a plurality of signals at the other end of said trunk line, discriminating means for operating said signals dependent upon th direction of the received current impulses and a plurality of relays at said first end oi the trunk line for varying the direction oi the transmitted impulses.

3. In a signalling system, a trunk line, means inductively coupled to one end of the trunk line for transmitting impulses thercover, a plurality of signals at the other end of said trunk line, discriminating means at said other end of the trunk line for operating said signals dependent upon the direction of the received impulses, a rectifier at said first end of the trunk line, and a relay for connecting said rectifier in the circuit of said transmitting means to limit the induced impulses to a certain direction only.

4 In a signalling system, a line, means at one end of said line for transmitting induced impulses thereover, said means including a transformer having its secondary winding connected to said line. a direct current circuit for the primary winding, and means for interrupting said circuit, two receiving devices at the other end of said line responsive to impulses in two directions, respectively, a rectifier at said first end of the line, and means for including said rectifier in the connection between the secondary winding of the transformer impulses to one direction to operate one of said devices.

5. In a signalling system, a line, means at one end of said line for transmitting induced impulses thereo-ver, said means including a transformer having its secondary winding connected to said line. a direct current circuit for the primary winding, and means for interrupting said circuit, two receiving devices at the other end of said line responsive to impulses in two directions, respectively. a rectifier at said first end of the line, means for including said rectifier in the connection between the secondary winding of the transformer and the line to limit the transmitted impulses to one direction to operate one of said devices, and means for reversing the connections to said line to reverse the direction of the transmitted impulses to operate the other of said devices.

6. In a signalling system, a line, means at one end of the line for transmitting induced impulses thereover, a receiving device at the other end of the line operated only by impulses in one direction, a second receiving device at said other end of the line operated only by impulses in the other direction, two switching devices at said first end of the line, means responsive to the operation of the first switching device for limiting the induced impulses to one direction only to operate said first receiving device, and means responsive to the operation of both of said switching devices for limiting the induced and the line to limit the transmitted I impulses to the other direction only to operate said second receiving device.

7 In a signalling system, a line, a receiving device at one end of said line operated only by impulses in one direction, a second receiving device operated only by impulses in the other direction, means at the other end of said line for generating induced impulses and transmitting the same over said line to operate both devices, a rectifier and two switching devices at said other end of the line, means responsive to the operation of one of said switching devices for connecting said rectifier in the circuit of said impulsing means to limit the transmitted impulses to one direction to operate only the first receiving device, and means responsive to the operation of the other switching device for reversing the connections to said line to reverse the direction of the transmitted impulses and operate only the second receiving device.

8. In combination, a transformer having its secondary winding connected to a trunk line, a direct current circuit including the primary winding of said transformer and a source of current, means for intermittently interrupting said circuit to induce impulses in said secondary winding to transmit current impulses in both directions over said trunk line, means for limiting the transmitted impulses to current pulses in one direction only, and means for limiting the transmitted impulses to current pulses in the other direction only.

9. In combination, a transformer having its secondary winding connected to a line, a direct current circuit including the primary winding of said transformer and a source of current, means for interrupting said circuit to induce impulses in said secondary winding transmitted in both directions over said line, a rectifier, means for connecting said rectifier in the circuit of said secondary Winding to limit the transmitted impulses to current flow in one direction only, and means for reversing the connections to said line to limit the transmitted impulses to current flow in the other direction only.

In witness whereof I hereunto subscribe my name this 24th day of June, A. D. 1931.

FRITZ LUBBERGER.

In witness whereof I hereunto subscribe my name this 24th day of June, A. D. 1931.

GERI-IARD ROTHERI. 

